A lubricant is a substance introduced between surfaces in mutual contact, for example, in machines and automobiles, to reduce friction between the surfaces. In general, the functions of the lubricant are to: (a) keep surfaces of moving components separated under all loads, temperatures and speeds, thus minimizing friction and wear; (b) act as a cooling fluid removing heat produced by friction or from external sources; (c) remain adequately stable in order to ensure uniform behavior over a forecasted useful life; and (d) protect surfaces of moving mechanical components from an attack of corrosive products formed during operation. In order to meet the various functions, one or more types of additives are added into a base oil in a lubricant composition. The additives are used to improve performance characteristics of the lubricants. The additives can be, for example, antioxidants, detergents, anti-wear substances, metal deactivators, corrosion inhibitors, and rust inhibitors.